The present invention relates generally to apparatus for applying heat and pressure to generally flat or sheet-like articles such as fabric and backing pieces, and to oven apparatus, conveyor apparatus and guide apparatus therefor, and apparatus for cleaning moving surfaces such as rollers and conveyor belts. More particularly, the present invention relates to a fusing machine.
A fusing machine as known in the garment industry applies heat and pressure to two or more superposed pieces of fabrics, backing materials, laminates, etc. to adhere or fuse them together. Typically, the fused or adhered pieces provide rigidity or reinforcement to parts of garments such as fronts, cuffs, collars, pockets, etc.
Known fusing machines include both the in-line type and the return-to-operator type. Pieces are fed to an in-line machine from one side of the machine and are discharged from the other side of the machine, as for example, in the machine described in U.S. Pat. No. 3,767,511. Typically a feed conveyor is disposed on one side of the machine to feed pieces to an oven in which the pieces are heated and pressure is applied to fuse the pieces, and either a discharge conveyor or a tray are disposed at the other side of the machine to receive fused pieces discharged from the oven. Known in-line fusing machines generally require a relatively large amount of floor space and utilize relatively large and energy inefficient ovens. In-line machines are known to utilize an opposed belt-type oven in which the pieces are engaged between two belts, or a drum-type oven in which the pieces are engaged between a drum and a belt or roller, or between two drums. Known return-to-operator machines typically use a drum-type oven.
Known ovens suffer from several drawbacks. The opposed belt-type ovens are usually quite large and poorly insulated, and therefore require a great deal of energy to heat. Moreover, some belt-type ovens apply heat by means of a large metal platen which requires a great deal of energy to heat. The drum-type ovens apply heat through a drum which is typically large and also requires a great deal of energy to heat.
Many known fusing machines also experience difficulties in maintaining the oven surfaces, i.e. drum, roller or belt surfaces, clean. For example, apparatus provided for cleaning those surfaces itself has to be periodically cleaned and heretofore necessitated shutting down the machine. Additionally, prior machines could not continue to operate if the oven surfaces were not clean. Thus, if an oven surface became thickened with accumulations, a residue or a piece of fabric or backing adhered to a drum or belt surface, the machine had to immediately be shut down to clean the belt or drum since the pressure part of the oven could not accommodate the increase in belt or drum surface height due to the accumulations, etc.
In belt-type ovens, the belt is typically driven by tensioning it around several rollers at least one of which was driven. Such an arrangement has required belt guidance apparatus to insure that the belt remains aligned on the drive roller. Some known guide apparatus axially moved one of the rollers or cylinders by a hydraulic or pneumatic system so as to maintain the belt aligned.
Many prior fusing machines, whether of the in-line or return-to-operator type, or using belt or drum-type ovens, utilize expensive penumatic or hydraulic systems for applying pressure to the pieces and/or for guiding the belts of feed, discharge and oven conveyors.
Thus, many prior fusing machines are inefficient and/or utilize complicated systems which have to be monitored relatively frequently and require maintenance or repair relatively often.
The present invention provides an improved fusing machine in which the drawbacks mentioned above are eliminated, and improved fusing machine subassemblies, as well as improved heat and pressure applying apparatus, improved oven apparatus, improved conveyor apparatus and guide apparatus therefor, improved apparatus for cleaning moving surfaces and other improved apparatus.